Intelligent waste management for aquaculture
The aim of the project, sponsored by the INCO 2 Programme, was to combine Western and Eastern know-how to deliver a zero discharge solution for aquaculture. Waste management is a serious issue for the rapidly growing aquaculture industry. The Institut fuer Meereskunde an der Universitaet, Kiel, (IFM-GEOMAR), a German member of the ZAFIRA consortium, performed a number of small-scale tests in the laboratory based on Recirculating aquaculture system (RAS) technology. They selected the European sea bass, Dicentrarchus labrax, as a model fish. Solid fish waste was eliminated from the tank by a combination of a swirl separator and foam fractionation, which removed large and small particles respectively. Ozone treatment was also applied to further improve water quality. Care was taken to minimise the energy and water replenishment requirements of the system without compromising the health of the fish. The trials, which lasted well over one year, were carried out in collaboration with a German SME, Erwin Sander Elektroapparatebau GmbH in Eltze. Close monitoring of total suspended solids and other parameters provided IFM-GEOMAR with the information necessary to design a detrivorous reactor to handle the RAS waste products. Chemical analysis of the waste stream provided insight into its potential use as a nutrient-rich feed for other organisms.
